Inset-type fastener elements are useful for connecting various types of structures to other structures or objects. An inset fastener element is generally anchored into a structure and has an engagement portion to which a screw fastener or the like is secured in order to connect an object to the structure. This arrangement is particularly advantageous when a strong connection between the structure and the object cannot readily be obtained by securing the fastener directly to the structure without an intervening fastener element.
Sandwich panels of the type used extensively in the aircraft and marine industries are one type of structure which is commonly connected to other structures or objects by use of inset fastener elements. In order to provide a secure anchor in the cellular honeycomb core of the panel, the inset fastener element is molded into a cavity formed in the core by use of a binding (potting) material. In such molded-in installations, it is difficult to precisely align the fastener element with the fastener receiving hole or other engagement means in the object or structure to be connected to the panel. One way of compensating for the difficulty in obtaining alignment is to allow the fastener element to automatically adjust for misalignments by providing a fastener element with a floating member.
Inset fastener elements having floating members that automatically adjust for misalignments are disclosed in U.S. Pat. No. 4,973,208, granted Nov. 27, 1990, to the present inventor; U.S. Pat. No. 3,504,723, granted Apr. 7, 1970, to K. V. Cushman et al.; and U.S. Pat. No. 3,339,609, granted Sep. 5, 1967, to K. V. Cushman. The fastener element disclosed in each of these patents has an outer disk portion that reacts loads imposed on the floating member by the fastener. The outer disk has an inwardly facing radial surface that engages an outer radial surface of the floating member to transmit the forces. In this type of arrangement, the ability of the fastener element to react the forces without structural damage to the element depends on the strength of the outer disk and its connections to other portions of the element. The primary object of the present invention is to provide an inset fastener element with a floating member that provides greater strength and capability of reacting loads than known fastener elements, such as those disclosed in the three patents cited herein.